It is previously known from the patents U.S. Pat. Nos. 3,416,578 and 4,768,289 to coat a severely loaded edge with some hard and wear-resistant metal layer at the nose of such chainsaws that do not have a nose sprocket. This applies to chainsaws used to cut minerals, or to cut wood where mineral grains may be lodged in the bark or stirred from the ground. Traditionally the edge has been coated with cobalt alloys, such as known by the trademark "Stellite", applied by gas welding. These have a very high surface tension when molten, and will not run off or sag until they have solidified. The weld metal will form a thick rounded bead along the edge, and much of the deposited metal will have to be ground off to form a smooth running face for the saw chain.
Cobalt alloys are relatively expensive, and not very resistant to acidic wood. Nickel alloys with equal or better resistance and lower cost are known, but can not be used in the same way since they have too low surface tension when molten. They might be applied through flame or plasma spraying, where a finely powderized alloy is introduced in a stream of hot gas and transferred as molten droplets to the surface of a cold work piece. This method will also consume more material than will ultimately stay on the guide bar and requires much work to grind away the excess.
Hardfacing alloys can also be applied according to the patent U.S. Pat. No. 5,144,867 by inserting one end of a guide bar blank in a mold filled with powderized alloy, heating the mold and the blank to the melting point of the alloy to let the alloy form a wear resisting layer on the blank, and finally milling or grinding a chain groove through the layer. According to that patent, the grinding work on the edges and on the outside of the guide bar is reduced.